Connector having twin camming surfaces



Oct. 22, 1963 R. L. BURG CONNECTOR HAVING TWIN CAMMING SURFACES Filed Aug. 17. 1960 INV EN TOR. @4400 Laws/res 54/4 6 United States Patent 3,107,571 CGNNECTQR HAVING TWEN QAMMENG $URFACES Roland L. Burg, Brooklyn, N33 Row Products Co, 254 Lawrence Ave., Lawrence, Long Island, FLY.) Filed Aug. 17, 1%9, Ser. 50,152 2 Qlaims. ((Zl. 85-7) This invention relates to connectors for self-formmaintaining objects and more particularly to a novel quickly attachable and detachable connector for such objects.

Conventionally, attachable and detachable means for self-forrmmaintaining objects of the character described constitute screws, or nuts and bolts, or rivets. Such means necessitate the use of tools, take a considerable amount of time to employ, and may even involve a high degree of manual skill or dexterity.

A principal object of my present invention is to provide a device of the character described which is simple and durable in construction, is usable in almost all instances where conventional attachable and detachable con necting means are employable, and can be inexpensively mass produced in very large quantities in a wide variety of sizes.

It is another object of my present invention to provide a device of the character described which is very simple to use, produces a very positive and strong securement between the objects joined and can, if desired, be made entirely from sheet metal by very inexpensive and rapid stamping operations.

Other objects of my invention in part will be obvious and in part will be pointed out hereinafter.

My invention accordingly consists in the features of construction, combinations of elements and arrangements of parts which will be exemplified in the connectors hereinafter described and of which the scope of application will be indicated in the appended claims.

In the accompanying drawings in which are shown various possible embodiments of my invention:

FIG. 1 is a side View showing a connector embodying my instant invention in closed condition as used to secure two self-form-maintaining objects to one another;

FIG. 2 is a view similar to FIG. 1, but illustrating my connector in conjunction with thinner objects than are shown in FIG. 1;

FIG. 3 is a view similar to FIG. 1 showing my connector in open condition;

FIG. 4 is an exploded view of my connector and the two objects to be joined, showing how the parts of the connector are employed to secure the objects to one another;

FIG. 5 is a top view of the cam part of the connector showing a detail of the construction thereof;

FIG. 6 is an enlarged sectional view taken substantially along the line 66 of FIG. 5;

FIG. 7 is a sectional view taken substantially along the line 7-7 of FIG. 6; and

FIG. 8 is a perspective view of a stud embodying a modified form of my invention.

Generally, the connector embodying the present invention comprises a cam and a stud, the stud having a base and a post extending therefrom. The stud post is freely axially receivable without rotation in registered openings in the objects to be secured to one another, and the cm and stud which initially are entirely disassembled (not connected together or even in contact with one another) are adapted to be detaohably interengaged with the stud post extending through said registered openings. The stud base includes at least one projection adapted to abut the object adjacent to it on the post. The cam includes an integral shaft arranged to be captively rotatively engaged in a bayonet slot formed in the post, so that after the post has been inserted through the registered openings of the objects with its projection contacting its adjacent object, the stud can be locked to the cam by wedging of the protuberance of the cam against the object that is adjacent the cam, thereby rapidly tightly securing together the objects to be joined.

Referring now in detail to the drawings, the reference numeral 10 denotes a connector embodying the present invention and comprising two parts, to wit, a stud l2 and a cam 14-. Desirably, the connector is made of strong light sheet metal, such, for example, as 10 to 24 gauge cold-rolled steel (the thickness will depend upon the expected severity of use), and the parts are fabricated by stamping operations. The stud and cam can, however, be die cast, of zinc alloy, for example, or forged or cast, or they may be made by molding from a strong, durable plastic material, such as polystyrene the physical and mechanical properties of which have been improved by addition of a Buna S rubber. Fabrication by stamping of sheet metal is preferred because of the low manufacturing costs and high rates of production made possible thereby; in stamping, for instance, the whole operation for each part of the connector can be carried out on a power press wherein the metal is fed automatically through progressive dies for blanking and forming.

The stud comprises a base 16 integral with a hollow elongated circular post :13 having at least one bayonet slot 20 therein. In the device illustrated, two such slots are provided; the purpose of this will become apparent hereinafter. Each slot includes a longitudinal through channel 22 opening in the direction of the base 16 and having a closed end 24 remote from the base. The channel 22 communicates at its open end with one end of a transverse i.e., circumferential, through channel 26 which in turn communicates at its other end with the external surface of the post. The channels mutually define a hook 28 facing in the direction of the stud base.

At said base 16 of the stud a cylindrical head 30 is provided of larger diameter than the post 18. The stud is fashioned from sheet metal by a deep drawing operation which leaves its top wall 31 integral with the tubular side walls of the post.

The cam 14 constitutes a pair of similarly shaped spaced parallel elongated side plates 32, 34- joined by a skeletonized back wall 36 integral therewith. More particularly, the back wall includes a large opening 38 as wide as the post 18. The lower portion of the back wall constitutes a shaft 4% which for sturdiness is of curved cross-sections (see FIG. 7). The side portions 42 of the back wall act to reinforce the side walls 32, 34. A camming protuberance d4 eccentric with respect to the shaft 40 is formed at one end of each side plate, the two protuberances being identical in size, contour and orientation. The protuberances are spaced transversely a distance greater than the diameter of the post. Although the protuberances, as shown, project forwardly, they will function satisfactorily it differently oriented, e.g., project rearwardly. At the upper edge of the back wall 36 an integral transverse flange 46 is provided. The flange 46 extends at right angles to the back wall and is located on the same side thereof as the protuberances. Said flange includes a transverse slot 48 the purpose of which will become apparent hereinafter. Also, a hexagonal opening 50 is provided in each side plate 32, 34 for a purpose to be set forth below.

The portion of the cam remote from the protuberances 4-4 constitutes generally a handle 52. The various parts of the cam will hold their mutually respective locations by virtue of the strength of the metal employed.

The connector is usable with two or more objects having registered openings therein. In the drawings, two

a objects 54, 55 having registered circular through openings 58, 6b are shown (see FIG. 2). Said openings are of such size that the post 18 is freely axially receivable therein without rotation; they are not so large as to admit the head of the stud or the protuberances of the cam in the closed position thereof.

The connector operates as follows: the post is inserted through the registered openings 58, 66). Next, the cam is turned to present maximum clearance between the pro tuberances 44 and the objects to be joined (the cam orientation in PEG. 3 is exemplificative), the purpose of this being to facilitate the next step which is insertion of the shaft 40 into a bayonet slot 29. After such innesses or with a plurality of objects. Thus, the objects to be joined may be of such combined thickness that the slot 2%} nearest the base of the stud is covered by an object or part of it, or the slot, though not covered,

sertion of the shaft, the handle of the cam is rotated to I wedge the protuberances 44- against the object 56, forcing such object against the object 54 which in turn is forced against the head 39. In this manner the objects are locked together.

In operation of the connector, the shaft 49 turns at the closed end 2 of the slot 29, and the hook 2% prevents the shaft from coming out of the slot as the protuherances are being wedged against the object 56 and thereafter.

It will be observed (see FIG. 3) that when the cam 14 initially is coupled with the stud 12 (by insertion of the shaft 49 in a bayonet slot) the shaft 4% is within the post 18 although the upper end of the back wall is outside the post. This arrangement is accomplished by virtue of the opening 38 which at such times accommodates a portion of the post.

Attention also is directed to the different angular positions of the cam 14 in FIGS. 1 and 2. In FIG. 1 the connector is employed to interengage thicker objects 54, 5s than those illustrated in FIG. 2; hence a lesser angular motion of the cam is required for the PEG. 1 arrangement than for the FIG. 2 arrangement in order to wedge the cam in locking position. Moreover, in a preferred form of my invention the connector is made to join two objects 5 5, 56 of specific combined thicknesses at the openings 53; 6b; in this case the protuberances are so designed that the radius R of maximum eccentricity of each protuberance is barely, e.g. three-thousandths of an inch, in excess of the distance from theshaft 4i) to the outer object 56 when the connector is locked. Accord ingly, when the handle 52 is swung to locked position, the radii of maximum eccentricity will be forced past dead center position with respect to the object 56, the side plates being sufficiently resilient to permit this to take place; thereafter when pressure on the handle is released any force tending to separate the two objects will urge the cam to turn in a locking direction and reliance will not have to be placed solely on the wedging action between the protuberancesand the outer object on as it is when the connector is used as shown in FIG. 1.

By using the protuberances, one on each side of the post, the forces acting on the objects and cam are balanced and twisting of the cam and post thereby is obviated.

As is apparent from the foregoing, objects to be joined are easily secured to one another in a few seconds time by means of a connector embodying my instant invention, and this is accomplished without the use of any tools and without the need for any mechanical skill or dexerity. Added leverage is obtainable by lengthening the handle and may be desirable, for example, where the surface adjacent to the protuberances is very smooth or where very great pressure between the objects to be joined is required. Of course, if desired, extra leverage can be obtained by use of a tool; for example, an Allen wrench may be employed in connection with either opening 5% of the handle or a screw-driver used in conjunction with the slot 48 thereof.

The provision of more than one slot 2% permits a connector of the character described having a particular general size to be used with objects of different thickmay be too close to the objects when the latter are seated on the head 3% to permit proper manipulation of the cam for the required wedging of the protuberances thereof. in such cases, a second slot 20 further away from the base could be employed, whereas if only one slot were present, a diiferent size connector would be nee red. The provision of more than one slot permits a connector including a stud post having crosssection of a particular size to be used with objects varying considerably as to thickness or number of objects to be long as the registered openings therein are of appropriate,

size.

The instant connector can be made in any desired size, and the dimensions of the various parts thereof are Widely variable during manufacture. For example, the stud post can be varied in length, number of slots, size of slots, size or shape of the head 30, etc. Likewise, the

cam protuberances may be larger or smaller, the handle,

shorter or longer, and soon. As a result, connectors of the character described can be made for practically all uses; for example, connectors can be provided having thin long posts, thin short posts, short heads, large heads, non-circular heads, etc., so that practically every conceivable fit, as far as joining different numbers of objects of different types and sizes is concerned, can be made as long as the objects can be provided with registered openings.

The wedging engagement between the protuberancesand the adjacent object may be made even more positive by roughening the edges of the protuberances, as by knurling. Since this may, however, to some extent deform the surface of the adjacent object, knurling is not always desirable. Although the post 18 and the registered openings 58, 6% have been described and shown as circular, they may be of any desired shape so long as they are matched or so long as the post is receivable in the registered openings as hereinbefore described. Also, the shaft 40 may be of any desired cross-section and the slots 20 need not have the specific contours shown so long as they arev capable of captively rotatively receiving the shaft 40 during and after wedging of the cam protuberances.

Another simple alternative form of stud 62 is shown in FIG. 8. Said stud is essentially identical to the stud l2 and varies only in the construction of its base which instead of being formed with a head 3%) is provided with a tail 6d and plural noses 66. Preferably the tail 64 and one nose 66 are diametrica ly opposed and extend away from the post 68 of the stud in opposite directions and have the surfaces thereof which face the bayonet slot 76 in the post disposed at right angles to the post. The remaining noses are in quadrature to the tail and said one nose. The stud d2 can be made by a stamping operation and bent to its final shape, the metal thereof being.

sufficiently sturdy to retain the shape.

It should be apparent from the foregoing that the present invention permits inexpensive production in tremendous quantities of a wide variety of the instant novel connectors adaptable for a wide variety of uses in rapidly securing objects to one another.

It thus will be seenthat I have provided connectors which achieve the various objects of my invention and are well adapted to meet the conditions of practical use.

As various possible embodiments might be made of the above invention and as various changes might be made in the embodiments above set forth, it is to be understood that all matter herein described or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Having thus described the invention, there is claimed as new and desired to be secured by Letters Patent:

1. A rapidly attachable and detachable connector for securing to one another objects having registered openings therein, said connector comprising a cam and a stud, the stud having a base and a post extending therefrom, said post being freely axially receivable in the registered openings of said objects, said base having at least one transverse dimension larger than a corresponding dimension of the post, whereby to provide a projection adapted to abut the object adjacent to the base, said cam constituting a pair of sheet metal broad fiat side walls joined by a sheet metal bar in one piece with said walls extending between said walls and at right angles thereto, the ends of said bar being located at registered points on the edges of said side walls, said stud having a slot therein extending from a mouth at a side of the stud to within the stud and ending within the stud in a closed end that is more remote from the base than the mouth of the slot, said sheet metal bar constituting a pivot shaft adapted to be inserted to the closed end of said slot for detachably rotatively interengaging the cam and the stud with the stud post extending through the registered openings in the objects to be attached to one another, the planes of said sheet metal side walls being parallel to one another and to the longitudinal axis of the stud and said side walls being located on and close to opposite sides of the post when the pivot shaft engages said closed end, the side edges of said fiat walls including registered portions having curved shapes which are eccentric to the pivot shaft so as to provide narrow twin protuberances located on opposite sides of the post and arranged to be wedged tightly against the adjacent object when the cam is turned about the pivot shaft relative to the post whereby the objects are secured to one another, said cam further including a handle in one piece with said side walls and extending between the same and located in a direction from th pivot shaft which is substantially at right angles to the direction from the pivot shaft to the point of greatest eccentricity on the side edges, said handle further being located on the side of the pivot shaft opposite to the side initially facing said objects when the pivot shaft engages said closed end, said handle including a back wall in one piece with the two parallel sheet metal side walls and connecting the edges of said side walls that also are connected by the pivot shaft, said back wall lying in a plane which intersects the pivot shaft, said handle further including a member at right angles to said back wall and extendingfrom the back wall in the direction that the cam is turned to wedge against the adjacent object, said member extending a distance sufiicient to abut the adjacent object and thereby limit rotation of said cam about the shaft, said back wall ending at a distance spaced from said shaft to form an opening that partially accommodates the post when the cam is disengaged from the adjacent object and the pivot shaft engages the slot.

2. A connector as set forth in claim 1 wherein the stud includes plural slots parallel to one another and spaced from one another axially along the stud.

References Cited in the file of this patent UNITED STATES PATENTS 

1. A RAPIDLY ATTACHABLE AND DETACHABLE CONNECTOR FOR SECURING TO ONE ANOTHER OBJECTS HAVING REGISTERED OPENINGS THEREIN, SAID CONNECTOR COMPRISING A CAM AND A STUD, THE STUD HAVING A BASE AND A POST EXTENDING THEREFROM, SAID POST BEING FREELY AXIALLY RECEIVABLE IN THE REGISTERED OPENINGS OF SAID OBJECTS, SAID BASE HAVING AT LEAST ONE TRANSVERSE DIMENSION LARGER THAN A CORRESPONDING DIMENSION OF THE POST, WHEREBY TO PROVIDE A PROJECTION ADAPTED TO ABUT THE OBJECT ADJACENT TO THE BASE, SAID CAM CONSTITUTING A PAIR OF SHEET METAL BROAD FLAT SIDE WALLS JOINED BY A SHEET METAL BAR IN ONE PIECE WITH SAID WALLS EXTENDING BETWEEN SAID WALLS AND AT RIGHT ANGLES THERETO, THE ENDS OF SAID BAR BEING LOCATED AT REGISTERED POINTS ON THE EDGES OF SAID SIDE WALLS, SAID STUD HAVING A SLOT THEREIN EXTENDING FROM A MOUTH AT A SIDE OF THE STUD TO WITHIN THE STUD AND ENDING WITHIN THE STUD IN A CLOSED END THAT IS MORE REMOTE FROM THE BASE THAN THE MOUTH OF THE SLOT, SAID SHEET METAL BAR CONSTITUTING A PIVOT SHAFT ADAPTED TO BE INSERTED TO THE CLOSED END OF SAID SLOT FOR DETACHABLY ROTATIVELY INTERENGAGING THE CAM AND THE STUD WITH THE STUD POST EXTENDING THROUGH THE REGISTERED OPENINGS IN THE OBJECTS TO BE ATTACHED TO ONE ANOTHER, THE PLANES OF SAID SHEET METAL SIDE WALLS BEING PARALLEL TO ONE ANOTHER AND TO THE LONGITUDINAL AXIS OF THE STUD AND SAID WALLS BEING LOCATED ON AND CLOSE TO OPPOSITE SIDES OF THE POST WHEN THE PIVOT SHAFT ENGAGES SAID CLOSED END, THE SIDE EDGES OF SAID FLAT WALLS INCLUDING REGISTERED PORTIONS HAVING CURVED SHAPES WHICH ARE ECCENTRIC TO THE PIVOT SHAFT SO AS TO PROVIDE NARROW TWIN PROTUBERANCES LOCATED ON OPPOSITE SIDES OF THE POST AND ARRANGED TO BE WEDGED TIGHTLY AGAINST THE ADJACENT OBJECT WHEN THE CAM IS TURNED ABOUT THE PIVOT SHAFT RELATIVE TO THE POST WHEREBY THE OBJECTS ARE SECURED TO ONE 